[timer] Remove now-obsolete references to TIMER_BIOS and TIMER_RDTSC

src/config/general.h

  * Timer configuration
  *
  */
-#define TIMER_BIOS		/* 18Hz BIOS timer */
-#define TIMER_RDTSC		/* CPU TimeStamp Counter timer */
 #define BANNER_TIMEOUT	20	/* Tenths of a second for which the shell
 				   banner should appear */
 

src/core/config.c

 REQUIRE_OBJECT ( syslog );
 #endif
 
-/*
- * Drag in all requested timers
- */
-#ifdef TIMER_BIOS
-REQUIRE_OBJECT ( timer_bios );
-#endif
-#ifdef TIMER_RDTSC
-REQUIRE_OBJECT ( timer_rdtsc );
-#endif
-
 /*
  * Drag in all requested network protocols
  *